A semiconductor device to be mounted on a substrate of electronic equipment is manufactured by means of slicing into pieces a semiconductor chip made up of discrete semiconductor devices from a semiconductor wafer, wherein integrated circuits are fabricated in the respective discrete semiconductor devices in a wafer state. With a recent increase in the degree of difficulty in handling a semiconductor chip resultant from a decrease in thickness of the semiconductor chip, there has been proposed plasma dicing for dicing a semiconductor wafer into pieces of semiconductor chips by means of plasma etching.
Plasma dicing is to etch a semiconductor wafer by means of plasma while the semiconductor wafer except for scribe lines showing grid-shaped split positions is masked by means of a resist film, thereby cutting the semiconductor wafer along the scribe lines. Therefore, plasma dicing requires a step of making a mask over the semiconductor wafer. A mask has heretofore been made by means of a photolithography (see Patent Document 1) for transferring a scribe line pattern by use of a photosensitive material or a method (see Patent Document 2) for eliminating a scribe line area on a mask layer formed over a surface of a semiconductor wafer by irradiation of a laser beam to thereby make a mask.